The study presented was conducted to analyze the effects of obsessive-compulsive symptoms on patients' quality of life and the costs incurred by patients and society for the treatment of obsessive-compulsive disorder (OCD). To accomplish this, a detailed 410-item questionnaire of psychosocial function and economic cost was sent to every fourth member of the Obsessive Compulsive Foundation. Of the 2,670 members who received the survey, 701 (26.9%) returned it. Outcome measures included symptomatology, course of illness, impact of illness on psychosocial and other functioning, effects of diagnosis and treatment, and economic consequences. The demographics of this group were similar to those in smaller treatment-seeking clinical samples, but not necessarily to OCD sufferers within the US population as a whole. More than half of the patients reported moderate to severe interference in family relationships, socializing, and ability to study or work, secondary to OCD symptoms. A 10.2-year gap was observed between the onset of symptoms and the first attempt to seek professional help, and a 17.2-year gap was observed between the onset of symptoms and receipt of effective treatment. Specific treatments, such as serotonin reuptake inhibitors and behavior therapy showed greater symptom improvement, and significantly reduced the total annual fees incurred by OCD patients when compared with nonspecific treatments. Our study results indicate that OCD has a profound effect on psychosocial functioning and quality of life. Large direct costs for OCD, and even larger indirect costs due to lost wages and underemployment were found. Greater awareness of OCD among practitioners may result in earlier diagnosis and more appropriate and cost-effective treatments.